Reduction of household air pollution through clean fuel intervention and recovery of cellular immune balance.

BACKGROUND: We conducted a clean fuel intervention trial (Bangladesh Global Environmental and Occupational Health (GEOHealth) (NCT02824237) with liquefied petroleum gas (LPG) for 26 months among rural Bangladeshi women chronically exposed to household air pollution (HAP) from biomass fuel (BMF) use. We aimed to evaluate the effect of HAP reduction following LPG intervention on immune response outcome. METHODS: We supplied LPG cook stove and refills in cylinder in 200 households for 26 months. We measured personal exposure to HAP [particulate matter 2.5 (PM2·5), black carbon (BC) and carbon monoxide (CO)] in 200 women (main cook) by personal monitors at pre- and post-intervention. Immune function was assessed before and after intervention, in blood collected within 2 weeks of HAP measurements. Primary endpoints included reduction in HAP, lymphocyte proliferation and oxidative stress response, and alterations in T and B cell proportions. FINDINGS: Exclusive LPG use for 26 months resulted in significant reduction in PM2·5 (43.5%), BC (13%) and CO (48%) exposure in the women. For one unit decrease in BC, Treg cells and memory B cells increased by 7% and 34% respectively, in the peripheral circulation. One unit decrease in CO was significantly associated with increase in early B cells and plasmablasts by 66% and 5% respectively. For one unit decrease in BC, percent-dividing cells, proliferation and expansion indices increased by 2%, 0.4%, and 1%, respectively. INTERPRETATION: Reduced personal exposure to HAP through clean fuel intervention was related to a return towards cellular immune balance.

Personal exposure to household air pollution and lung function in rural Bangladesh: A population-based cross-sectional study.

We assessed whether personal exposure to household air pollution [PM2.5 and black carbon (BC)] is associated with lung functions (FEV1, FVC, and their ratio) in non-smoking adults in rural Bangladesh. We measured personal exposure to PM2.5 using gravimetric analysis of PM2.5 mass and BC by reflectance measurement between April 2016 and June 2019. The average 24-hour PM2.5 and BC concentration was 141.0µgm-3 and 13.8µgm-3 for females, and 91.7 µgm-3 and 10.1 µgm-3 for males, respectively. A 1 µgm-3 increase in PM2.5 resulted in a 0.02 ml reduction in FEV1, 0.43 ml reduction in FVC, and 0.004% reduction in FEV1/FVC. We also found a similar inverse relationship between BC and lung functions (9.6 ml decrease in FEV1 and 18.5 ml decrease in FVC per 1µgm-3 increase in BC). A higher proportion of non-smoking biomass fuel users (50.1% of the females and 46.7% of the males) had restrictive patterns of lung function abnormalities, which need further exploration.

Association of household air pollution with cellular and humoral immune responses among women in rural Bangladesh.

Household air pollution (HAP) arising from combustion of biomass fuel (BMF) is a leading cause of morbidity and mortality in low-income countries. Air pollution may stimulate pro-inflammatory responses by activating diverse immune cells and cyto/chemokine expression, thereby contributing to diseases. We aimed to study cellular immune responses among women chronically exposed to HAP through use of BMF for domestic cooking. Among 200 healthy, non-smoking women in rural Bangladesh, we assessed exposure to HAP by measuring particulate matter 2.5 (PM2.5), black carbon (BC) and carbon monoxide (CO), through use of personal monitors RTI MicroPEM™ and Lascar CO logger respectively, for 48 h. Blood samples were collected following HAP exposure assessment and were analyzed for immunoprofiling by flow cytometry, plasma IgE by immunoassay analyzer and cyto/chemokine response from monocyte-derived-macrophages (MDM) and -dendritic cells (MDDC) by multiplex immunoassay. In multivariate linear regression model, a doubling of PM2.5 was associated with small increments in immature/early B cells (CD19+CD38+) and plasmablasts (CD19+CD38+CD27+). In contrast, a doubling of CO was associated with 1.20% reduction in CD19+ B lymphocytes (95% confidence interval (CI) = -2.36, -0.01). A doubling of PM2.5 and BC each was associated with 3.12% (95%CI = -5.85, -0.38) and 4.07% (95%CI = -7.96, -0.17) decrements in memory B cells (CD19+CD27+), respectively. Exposure to CO was associated with increased plasma IgE levels (beta(ß) = 240.4, 95%CI = 3.06, 477.8). PM2.5 and CO exposure was associated with increased MDM production of CXCL10 (ß = 12287, 95%CI = 1038, 23536) and CCL5 (ß = 835.7, 95%CI = 95.5, 1576), respectively. Conversely, BC exposure was associated with reduction in MDDC-produced CCL5 (ß = -3583, 95%CI = -6358, -807.8) and TNF-α (ß = -15521, 95%CI = -28968, -2074). Our findings suggest that chronic HAP exposure through BMF use adversely affects proportions of B lymphocytes, particularly memory B cells, plasma IgE levels and functions of antigen presenting cells in rural women.

Exposure to household air pollutants and endothelial dysfunction in rural Bangladesh: A cross-sectional study.

More than one third of world's population use biomass fuel for cooking that has been linked to an array of adverse health hazards including cardiovascular mortality and morbidity. As part of Bangladesh Global Environmental and Occupational Health (GEO Health) project, we assessed whether household air pollution (HAP) was associated with dysfunction in microvascular circulation (measured by reactive hyperemia index [RHI]). METHODS: We measured exposure to HAP (particulate matter [PM2.5], carbon monoxide [CO], and black carbon [BC]) for 48 hours of 200 healthy nonsmoker adult females who used biomass fuel for cooking. Exposure to PM2.5 and BC were measured using personal monitor, RTI MicroPEM (RTI International, NC) with an internal filter that had been both pre- and post-weighed to capture the deposited pollutants concentration. Lascar CO logger was used to measure CO. Endothelial function was measured by forearm blood flow dilatation response to brachial artery occlusion using RHI based on peripheral artery tonometry. A low RHI score (<1.67) indicates impaired endothelial function. RESULTS: Average 48 hours personal exposure to PM2.5 and BC were 144.15 µg/m3 (SD 61.26) and 6.35 µg/m3 (SD 2.18), respectively. Interquartile range for CO was 0.73 ppm (0.62-1.35 ppm). Mean logarithm of RHI (LnRHI) was 0.57 in current data. No statistically significant association was observed for LnRHI with PM2.5 (odds ratio [OR] = 0.97; 95% confidence interval [CI] = 0.92, 1.01; P = 0.16), BC (OR = 0.85; 95% CI = 0.72, 1.01; P = 0.07), and CO (OR = 0.89; 95% CI = 0.64, 1.25; P = 0.53) after adjusting for potential covariates. CONCLUSIONS: In conclusion, HAP was not associated with endothelial dysfunction among nonsmoking females in rural Bangladesh who used biomass fuel for cooking for years.

Household biomass fuel use is associated with chronic childhood malnutrition: Result from a nationwide cross-sectional survey in Bangladesh.

Despite significant investment, childhood malnutrition continues to be a significant public health problem especially in least developed countries. The aim of this study was to find association between household biomass fuel (BMF) use and childhood malnutrition in Bangladesh using data from Demographic and Health Survey 2011. We included a total 6891 children under 5 years of age in the analysis. The prevalence of wasting, underweight, and stunting from BMF using household was 16.1% (n = 997; 95%CI, 15.1-17.3), 39.0% (n = 2399; 95%CI, 37.1-40.9), and 43.3% (n = 2620; 95%CI, 41.6-45.1), respectively. Underweight and stunting were significantly higher among children from households using BMF compared with the children from CF using households (underweight, biomass vs clean fuel: 39.0% vs. 23.5%, p < 0.001; stunting, biomass vs clean fuel: 43.3 vs. 31.5%, p < 0.001). The use of BMF in the household was significantly associated with underweight (OR = 1.38; 95%CI: 1.10-1.73) and stunting (OR = 1.58; 95%CI: 1.18-1.98) among children <5 years of age after adjusting possible confounders in mixed effect logistic regression analysis. This study found a significant association between chronic childhood malnutrition and household BMF use which is indicating possible alternative risk factor for malnutrition. Further prospective research is required to explore the mechanism of how BMF use results in chronic malnutrition.

Undiagnosed Isolated Systolic and Diastolic Hypertension Subtypes and Their Correlates in Bangladesh: A Nationwide Survey.

OBJECTIVES: This study was performed to identify the distribution of undiagnosed isolated hypertension subtypes and their correlates amongst adults aged 35 years and older in Bangladesh using data from the Bangladesh Demography and Health Survey 2011. METHODS: Out of a total of 17,964 selected households, 7,880 were included in the final analysis for this study. Systolic and diastolic blood pressure (BP) were measured 3× at 10-minute intervals. Hypertension subtypes were defined for individuals not under antihypertensive treatment as systolic-diastolic hypertension (SDH): systolic BP (SBP) ≥ 140 mm Hg and diastolic BP (DBP) ≥ 90 mm Hg; isolated diastolic hypertension (IDH): SBP < 140 mm Hg and DBP ≥ 90 mm Hg, and isolated systolic hypertension (ISH): SBP ≥140 mm Hg and DBP < 90 mm Hg. RESULTS: The predominant hypertension subtypes were SDH and IDH [5.2%; 95% confidence interval (CI): 4.7-5.1] followed by ISH (3.8%; 95% CI: 3.4-4.2). Multiple logistic regression showed that age and gender were significant predictors of ISH. SDH was associated with females [odds ratio (OR): 1.8; 95% CI: 1.3-2.6], the older age group (OR-7.4; 95% CI: 4.3-12.7), and overweight or obese individuals (OR: 1.6; 95% CI: 1.1-2.4). Non-manual work (OR: 1.5; 95% CI: 1.0-2.0]) and being overweight or obese (OR: 1.9; 95% CI: 1.4-2.8) were factors associated with IDH. CONCLUSION: ISH, IDH and SDH represent salient subtypes of hypertension in Bangladesh. To identify preventive intervention for averting adverse cardiovascular events, further research is needed.

Access to primary health care for acute vascular events in rural low income settings: a mixed methods study.

BACKGROUND: Cardiovascular diseases (CVDs) are the leading cause of global mortality. Among the CVDs, acute vascular events (AVE) mainly ischemic heart diseases and stroke are the largest contributors. To achieve 25% reduction in preventable deaths from CVDs by 2025, health systems need to be equipped with extended service coverage in order to provide person-centered care. The overall goal of this proposed study is to assess access to health care in-terms of service availability, care seeking patterns and barriers to access care after AVE in rural Bangladesh. We will consider myocardial infarction (MI) and stroke as acute vascular events. METHODS/DESIGN: We will conduct a mixed methods study in rural Matlab, Bangladesh. This study will comprise of a) health facility survey, b) structured questionnaire interview and c) qualitative study. We will assess service availabilities by creating an inventory of public and private health facilities. Readiness of the facilities to deliver services for AVE will be assessed through a health facility survey using 'service availability and readiness assessment' (SARA) tools of the World Health Organization (WHO). We will interview survivors of AVE and caregivers (present and accompanied the person during the event) of person who died from AVE for exploring patterns of care seeking during an AVE. For exploring barriers to access care for AVE, we will conduct in-depth interview with survivors of AVE and caregivers of the person who died from AVE. We will also conduct key informant interviews with the service providers at primary health care (PHC) facilities and government high level officials at central health administration of Bangladesh. DISCUSSION: This study will provide a comprehensive picture of access to primary health care services during acute cardiovascular events as stroke & MI in rural context of Bangladesh. It will explore available service facilities in rural area for management, utilization of services and barriers to access care during an acute emergency. This study will help to generate hypothesis, develop programs and policies for better access to care for AVE in similar rural settings considering barriers of access and improving utilization.

Obesity and its Relation With Diabetes and Hypertension: A Cross-Sectional Study Across 4 Geographical Regions.

BACKGROUND: The implications of rising obesity for cardiovascular health in middle-income countries has generated interest, in part because associations between obesity and cardiovascular health seem to vary across ethnic groups. OBJECTIVE: We assessed general and central obesity in Africa, East Asia, South America, and South Asia. We further investigated whether body mass index (BMI) and waist circumference differentially relate to cardiovascular health; and associations between obesity metrics and adverse cardiovascular health vary by region. METHODS: Using baseline anthropometric data collected between 2008 and 2012 from 7 cohorts in 9 countries, we estimated the proportion of participants with general and central obesity using BMI and waist circumference classifications, respectively, by study site. We used Poisson regression to examine the associations (prevalence ratios) of continuously measured BMI and waist circumference with prevalent diabetes and hypertension by sex. Pooled estimates across studies were computed by sex and age. RESULTS: This study analyzed data from 31,118 participants aged 20 to 79 years. General obesity was highest in South Asian cities and central obesity was highest in South America. The proportion classified with general obesity (range 11% to 50%) tended to be lower than the proportion classified as centrally obese (range 19% to 79%). Every standard deviation higher of BMI was associated with 1.65 and 1.60 times higher probability of diabetes and 1.42 and 1.28 times higher probability of hypertension, for men and women, respectively, aged 40 to 69 years. Every standard deviation higher of waist circumference was associated with 1.48 and 1.74 times higher probability of diabetes and 1.34 and 1.31 times higher probability of hypertension, for men and women, respectively, aged 40 to 69 years. Associations of obesity measures with diabetes were strongest in South Africa among men and in South America among women. Associations with hypertension were weakest in South Africa among both sexes. CONCLUSIONS: BMI and waist circumference were both reasonable predictors of prevalent diabetes and hypertension. Across diverse ethnicities and settings, BMI and waist circumference remain salient metrics of obesity that can identify those with increased cardiovascular risk.

Overweight and abdominal obesity as determinants of undiagnosed diabetes and pre-diabetes in Bangladesh.

BACKGROUND: Type 2 diabetes and pre-diabetes are an increasing pandemic globally and often remain undiagnosed long after onset in low-income settings. The objective of this study is to assess the determinants and prevalence of undiagnosed diabetes and pre-diabetes among adults in Bangladesh. METHODS: In an exploratory study, we performed oral glucose tolerance test on 1243 adults ≥20 years of age from urban Mirpur, Dhaka (n = 518) and rural Matlab, Chandpur (n = 725) who had never been diagnosed with diabetes or pre-diabetes. We collected data on socioeconomic, demographic, past medical history, physical activity, and measured weight, height, waist and hip circumferences, and blood pressure. Risk factors associated with undiagnosed diabetes and pre-diabetes were examined using a multiple logistic regression model. RESULTS: Overall prevalence of diabetes and pre-diabetes was 6.6 % (95 % CI 5.3, 8.1) and 16.6 % (14.5, 18.7) respectively, with both being significantly higher in urban than rural populations (diabetes 12.2 % vs 2.6 % respectively, p < 0.000; pre-diabetes 21.2 % vs 13.2 %, p < 0.001). After adjustment the variables, urban residence (OR 2.5 [95 % CI 1.02, 5.9]), age group 40-59 y (2.9 [1.7-5.2]), ≥60 y (8.1 [2.8-23.8]), overweight (2.2 [1.3-3.9]), abdominal obesity (3.3 [1.8-6.0]) and high WHR 5.6 (2.7-11.9) were all significant predictors of diabetes. Significant predictors of pre-diabetes included age group 40-59 (1.6 [1.1-2.2]), female sex (1.5 [1.0-2.2]), abdominal obesity (1.7 [1.2-2.4]) and high WHR (1.6 [1.2-2.3]). CONCLUSION: Both overweight and abdominal obesity contribute to the hidden public health threat of undiagnosed diabetes and pre-diabetes. Awareness raising and screening of high risk groups combined with a tailored approach are essential for halting the epidemic of diabetes and pre-diabetes in Bangladesh.

Awareness and control of hypertension in Bangladesh: follow-up of a hypertensive cohort.

OBJECTIVES: To assess the effect of awareness and advice to seek care on blood pressure (BP) control among patients with hypertension in Bangladesh. DESIGN: Longitudinal study. SETTING: The study was carried out in icddr,b surveillance sites at rural Matlab in Chandpur district and semi-urban Kamalapur in Dhaka, Bangladesh. PARTICIPANTS: Randomly selected men and non-pregnant women aged 20 years or older without any acute illness or history of any vascular events such as stroke or acute myocardial infarction. MAIN OUTCOME MEASURE: Hypertension was defined as systolic BP (SBP) ≥140 and/or diastolic BP (DBP) ≥90 mm Hg or as self-reported hypertension under medication. We advised patients to seek care from a qualified provider and to adopt a healthy lifestyle. We compared changes in BP from baseline to follow-up at around 6 months. RESULTS: Overall, 17.1% (n=287) of participants had hypertension at baseline with significantly higher prevalence in the semi-urban than in the rural population (23.6% vs 10.8%; p<0.001); half were unaware of their condition. At follow-up, 83% (n=204) reported a visit to any healthcare provider. In the semi-urban area, a higher proportion of patients visited medically qualified practitioners than in the rural area (76.7% vs 36.6%, p<0.000). SBP (-3.3±20.7 mm Hg; p<0.01) and DBP (-2.0±13.0 mm Hg; p<0.02) were lower at follow-up. Those who visited medically qualified practitioners had significant SBP (-3.9±22.4 mm Hg; p<0.03) and DBP (-2.7±14.1 mm Hg; p<0.02) reduction. BP reduction did not reach statistical significance among those visiting a pharmacist or their village doctors. Overall, half of the patients with hypertension achieved the BP control goal (BP<140/90 mm Hg). CONCLUSIONS: Awareness and simple health messages increase provider visit, reduce blood pressure and improve BP control in hypertensive Bangladeshis. Longer-term follow-up is required to verify the sustainability.

Consequences of hypertension and chronic obstructive pulmonary disease, healthcare-seeking behaviors of patients, and responses of the health system: a population-based cross-sectional study in Bangladesh.

BACKGROUND: Non-communicable diseases are a threat to human health and economic development of low-income countries. Hypertension (HT) and chronic obstructive pulmonary disease (COPD) are two major causes of deaths, worldwide. This study assesses the health status, health-care seeking, and health provider responses among patients with these conditions. METHODS: The study carried out population-based cross-sectional survey in a rural and an urban surveillance area in Bangladesh. It interviewed all patients identified with HT and COPD at home using a structured questionnaire on the health consequences, healthcare-seeking behaviours, and coping strategies. Qualitative techniques identified key factors relating to the behaviours of patients and providers. RESULTS: COPD and HT correlate with lower activities of daily living (ADL) scores. The odds ratio (OR) for ADL scores in the combied conditions are high (OR: 3.04, p < 0.05) as compared to hypertension. Financial crises occur significantly more frequently among COPD patients in the urban site as compared to those in rural ares (12.5% vs. 2.4%, p < 0.01). Self-treatment at the onset is common. Seeking care from trained providers is higher in urban settings and is higher for HT. Referral for both COPD and hypertension was inadequate until the disease severity increased. CONCLUSIONS: COPD and HT significantly are associated with lower ADL scores and financial problems. Public-sector primary healthcare facilities should be better organised to address both conditions with the aim to reduce household poverty.